First continuous high-resolution aerosol record from the East Greenland Ice Core Project (EGRIP), covering the last 15,000 years

2020 ◽  
Author(s):  
Camilla Marie Jensen ◽  
Tobias Erhardt ◽  
Giulia Sinnl ◽  
Hubertus Fischer
Keyword(s):  
High Resolution ◽  
Biomass Burning ◽  
Forest Fires ◽  
Ice Core ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Background Level ◽  
Volcanic Eruptions ◽  
Atmospheric Conditions ◽  
Data Set

<p>Ice sheets are reliable archives of atmospheric impurities such as aerosols and gasses of both natural and anthropogenic origin. Impurity records from Greenland ice cores reveal much information about previous atmospheric conditions and long-range transport in the Northern hemisphere going back more than a hundred thousand years.</p><p>Here we present the data from the upper 1,411 m from the EGRIP ice core, measuring conductivity, dust, sodium, calcium, ammonium, and nitrate. These records contain information about ocean sources, transport of terrestrial dust, soil and vegetation emissions as well as biomass burning, volcanic eruptions, etc., covering approximately the past 15,000 years. This newly obtained data set is unique as it provides the first high-resolution information about several thousands of years of the mid-Holocene period in Greenland that none of the previous impurity records from the other deep Greenland ice cores had managed to cover before due to brittle ice. This will contribute to further understanding of the atmospheric conditions for the pre-industrial period.</p><p>The ammonium record contains peaks significantly higher than the background level. These peaks are caused by biomass burning or forest fires emitting plumes of ammonia large enough so that they can extend to the free troposphere and be efficiently transported all the way to the Greenland ice sheet. Here we present preliminary results of the wild fire frequency covering the entire Holocene, where the wild fires are defined as outliers in the ammonium record of annual means.</p>

Forty years later: High resolution continuous flow analysis of the Dye3 ice core

2021 ◽  
Author(s):  
Helle Astrid Kjær ◽  
Margaret Harlan ◽  
Paul Vallelonga ◽  
Anders Svensson ◽  
Thomas Blunier ◽  
...  
Keyword(s):  
High Resolution ◽  
Forest Fires ◽  
Continuous Flow ◽  
Ice Core ◽  
Flow Analysis ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
The Core ◽  
Continuous Flow Analysis

<div><span><span>The Dye-3 ice core was drilled to bedrock at the Southern part of the central Greenland ice sheet (65°11'N, 43°50'W) in 1979-1981. The southern location is characterized by high accumulation rates compared to more central locations of the ice sheet. Since its drilling, numerous analyses of the core have been performed, and the ice has since been in freezer storage both in the USA and in Denmark.</span></span></div><div><span>In October and November 2019, the remaining ice, two mostly complete sections covering the depths of 1753–1820m and 1865–1918m of the Dye-3 core, were melted during a continuous flow analysis (CFA) campaign at the Physics of Ice, Climate, and Earth (PICE) group at the University of Copenhagen. The data represents both Holocene, Younger Dryas and Glacial sections (GS 5 to 12).</span></div><div> </div><div><span><span>The measured data consist chemistry and impurities contained in the ice, isotopes, as well as analysis of methane and other atmospheric gases. </span></span></div><div><span><span>The chemistry measurements include NH</span></span><span><span><sub>4</sub></span></span><span><span><sup>+</sup></span></span><span><span>, Ca</span></span><span><span><sup>2+</sup></span></span><span><span>, and Na</span></span><span><span><sup>+</sup></span></span><span><span> ions, which besides being influenced by transport, provide information about forest fires, wind-blown dust, and sea ice, respectively, as well as acidity, which aids in the identification of volcanic events contained in the core. The quantity and grain size distribution of insoluble particles was analyzed by means of an Abakus laser particle counter.</span></span></div><div> </div><div><span>We compare the new high-resolution CFA record of dye3 with previous analysis and thus evaluate the progress made over 40 years. Further we compare overlapping time periods with other central Greenland ice cores and discuss spatial patterns in relation to the presented climate proxies.</span></div>

scholarly journals Boreal fire records in Northern Hemisphere ice cores: a review

2016 ◽  
Vol 12 (10) ◽  
pp. 2033-2059 ◽  
Author(s):  
Michel Legrand ◽  
Joseph McConnell ◽  
Hubertus Fischer ◽  
Eric W. Wolff ◽  
Susanne Preunkert ◽  
...  
Keyword(s):  
High Resolution ◽  
Organic Carbon ◽  
Biomass Burning ◽  
Forest Fires ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
High Elevation ◽  
Potassium Nitrate ◽  
Fire Activity

Abstract. Here, we review different attempts made since the early 1990s to reconstruct past forest fire activity using chemical signals recorded in ice cores extracted from the Greenland ice sheet and a few mid-northern latitude, high-elevation glaciers. We first examined the quality of various inorganic (ammonium, nitrate, potassium) and organic (black carbon, various organic carbon compounds including levoglucosan and numerous carboxylic acids) species proposed as fire proxies in ice, particularly in Greenland. We discuss limitations in their use during recent vs. pre-industrial times, atmospheric lifetimes, and the relative importance of other non-biomass-burning sources. Different high-resolution records from several Greenland drill sites and covering various timescales, including the last century and Holocene, are discussed. We explore the extent to which atmospheric transport can modulate the record of boreal fires from Canada as recorded in Greenland ice. Ammonium, organic fractions (black and organic carbon), and specific organic compounds such as formate and vanillic acid are found to be good proxies for tracing past boreal fires in Greenland ice. We show that use of other species – potassium, nitrate, and carboxylates (except formate) – is complicated by either post-depositional effects or existence of large non-biomass-burning sources. The quality of levoglucosan with respect to other proxies is not addressed here because of a lack of high-resolution profiles for this species, preventing a fair comparison. Several Greenland ice records of ammonium consistently indicate changing fire activity in Canada in response to past climatic conditions that occurred during the last millennium and since the last large climatic transition. Based on this review, we make recommendations for further study to increase reliability of the reconstructed history of forest fires occurring in a given region.

scholarly journals Boreal fire records in Northern Hemisphere ice cores: A review

2016 ◽  
Author(s):  
Michel Legrand ◽  
Joseph McConnell ◽  
Hubertus Fischer ◽  
Eric W. Wolff ◽  
Susanne Preunkert ◽  
...  
Keyword(s):  
High Resolution ◽  
Organic Carbon ◽  
Black Carbon ◽  
Biomass Burning ◽  
Forest Fires ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
High Elevation ◽  
Fire Activity

Abstract. Here we review different attempts made since the early 1990s to reconstruct past forest fire activity using chemical signals recorded in ice cores extracted from the Greenland ice sheet and at a few mid-northern latitude, high-elevation glaciers. We first examined the quality of various inorganic (ammonium, nitrate, potassium) and organic (black carbon, various organic carbon compounds including levoglucosan and numerous carboxylic acids) species proposed as fire proxies in ice, particularly in Greenland. We discuss limitations in their use with respect to the considered time period (recent versus pre-industrial times), their atmospheric lifetime, and the relative importance of other non-biomass burning sources. Different high-resolution records obtained at several Greenland drill sites and covering various timescales, including the last century and Holocene, are discussed. We explore the extent to which atmospheric transport can modulate the record of boreal fires from Canada as recorded in Greenland ice. Ammonium, organic fractions (black carbon as well as organic carbon), and organic compounds like formate and vanillic acid are found to be good proxies for tracing past boreal fires in Greenland ice. We show that use of other species – potassium, nitrate, and carboxylates (except formate) – is complicated by either post-depositional effects or existence of large non-biomass-burning sources. The quality of levoglucosan with respect to other proxies is not addressed here because of the present lack of high-resolution profiles for this species, which does not allow for a fair comparison. Several Greenland ice records of ammonium consistently indicate changing fire activity in Canada in response to past climatic conditions that occurred during the last millennium and since the last large climatic transition. Based on this critical review, we make recommendations for further study to increase reliability of the reconstructed history of forest fires occurring in a given region.

scholarly journals A multi-ice-core, annual-layer-counted Greenland ice-core chronology for the last 3800 years: GICC21

2021 ◽  
Author(s):  
Giulia Sinnl ◽  
Mai Winstrup ◽  
Tobias Erhardt ◽  
Eliza Cook ◽  
Camilla Jensen ◽  
...  
Keyword(s):  
Ice Core ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Conclusive Evidence ◽  
Fine Tuning ◽  
Cosmogenic Radionuclides ◽  
Data Set ◽  
Annual Layer ◽  
One Year

Abstract. Ice-core timescales are vital for the understanding of past climate; hence they should be updated whenever significant amounts of new data can contribute to improvements. Here, the Greenland ice-core chronology was revised for the last 3835 years by synchronizing six deep ice-cores and three shallow ice-cores from the central Greenland ice sheet. A layer-counting bias was found in all ice cores because of site-specific signal disturbances, and a manual comparison of all ice cores was deemed necessary to increase timescale accuracy. A new method was applied by combining automated counting of annual layers on multiple parallel proxies and manual fine-tuning. After examining sources of error and their correlation lengths, the uncertainty rate was quantified to be one year per century. The new timescale is younger than the previous Greenland chronology by about 13 years at 3800 years ago. The most recent 800 years are largely unaffected by the revision, while the slope of the offset between timescales is steepest between 800 and 1000 years ago. Moreover, offset-oscillations of about 5 years around the average are observed between 2500 and 3800 years ago. The non-linear offset behavior is attributed to previous mismatches of volcanic eruptions, to the much more extensive data set available to this study, and to the finer resolution of the new ice-core matching. In response to volcanic eruptions, averaged water isotopes and layer thicknesses from Greenland ice cores provide evidence of notable cooling lasting for up to a decade, longer than reported in previous studies of volcanic forcing. By analysis of the common variations of cosmogenic radionuclides, the new ice-core timescale is found to be in alignment with the IntCal20 curve. Radiocarbon dated evidence found in the proximity of eruption sites such as Vesuvius or Thera was compared to the ice-core dataset; no conclusive evidence was found regarding if these two eruptions can be matched to acidity spikes in the ice cores. A hitherto unidentified cooling event in the ice cores is observed at about 3600 years ago (1600 BCE), which could have been caused by a large eruption which is, however, not clearly recorded in the acidity signal. The hunt for clear signs of the Thera eruption in Greenland ice-cores thus remains elusive.

Tephra in the Greenland Ice cores: Insights into Icelandic volcano-climate impacts

2021 ◽  
Author(s):  
Imogen Gabriel ◽  
Gill Plunkett ◽  
Peter Abbott ◽  
Bergrún Óladóttir ◽  
Joseph McConnell ◽  
...  
Keyword(s):  
High Resolution ◽  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Climate Impacts ◽  
Geochemical Analysis ◽  
Volcanic Events ◽  
Societal Impacts ◽  
The Impact ◽  
Ice Core Records

<p>Volcanic eruptions are considered as one of the primary natural drivers for changes in the global climate system and understanding the impact of past eruptions on the climate is integral to adopt appropriate responses towards future volcanic eruptions.</p><p>The Greenland ice core records are dominated by Icelandic eruptions, with several volcanic systems (Katla, Hekla, Bárðarbunga-Veiðivötn and Grimsvötn) being highly active throughout the Holocene. A notable period of increased Icelandic volcanic activity occurred between 500-1250 AD and coincided with climatic changes in the North Atlantic region which may have facilitated the Viking settlement of Greenland and Iceland. However, a number of these volcanic events are poorly constrained (duration and magnitude). Consequently, the Greenland ice cores offer the opportunity to reliably reconstruct past Icelandic volcanism (duration, magnitude and frequency) due to their high-resolution, the proximity of Iceland to Greenland and subsequent increased likelihood of volcanic fallout deposits (tephra particles and sulphur aerosols) being preserved. However, both the high frequency of eruptions between 500-1250 AD and the geochemical similarity of Iceland’s volcanic centres present challenges in making the required robust geochemical correlations between the source volcano and the ice core records and ultimately reliably assessing the climatic-societal impacts of these eruptions.</p><p>To address this, we use two Greenland ice core records (TUNU2013 and B19) and undertake geochemical analysis on tephra from the volcanic events in the selected time window which have been detected and sampled using novel techniques (insoluble particle peaks and sulphur acidity peaks). Further geochemical analysis of proximal material enables robust correlations to be made between the events in the ice core records and their volcanic centres. The high-resolution of these polar archives provides a precise age for the event and when utilised alongside other proxies (i.e. sulphur aerosols), both the duration and magnitude of these eruptions can be constrained, and the climatic-societal impacts of these eruptions reliably assessed.</p>

scholarly journals Local scale depositional processes of surface snow on the Greenland ice sheet

2021 ◽  
Author(s):  
Alexandra M. Zuhr ◽  
Thomas Münch ◽  
Hans Christian Steen-Larsen ◽  
Maria Hörhold ◽  
Thomas Laepple
Keyword(s):  
Spatial Scales ◽  
Ice Core ◽  
Negative Relationship ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Data Set ◽  
Climate Signal ◽  
Depositional Processes ◽  
Snow Deposition

Abstract. Ice cores from polar ice sheets and glaciers are an important climate archive. Snow layers, consecutively deposited and buried, contain climatic information of the time of their formation. However, particularly low-accumulation areas are characterised by temporally intermittent precipitation, which can be further re-distributed after initial deposition. Therefore, the local conditions of accumulation at an ice core site influence the quantity and quality of the recorded climate signal in proxy records. Local surface features at different spatial scales further affect the signal imprint. This study therefore aims to characterise the local accumulation patterns and the evolution of the snow height to describe the contribution of snow (re-)deposition to noise in climate records from ice cores. By using a photogrammetry Structure-from-Motion approach, we generated near-daily elevation models of the snow surface for a 195 m2 area in the vicinity of the deep drilling site of the East Greenland Ice Core Project in northeast Greenland. Based on the snow height information we derived snow height changes on a day-to-day basis throughout our observation period from May to August 2018. Specifically, the average snow height increased by ~11 cm. The spatial and temporal data set allowed an investigation of snow deposition versus depositional modifications. We observed irregular snow deposition, erosion, and the re-distribution of snow, which caused uneven snow accumulation patterns, a removal of more than 60 % of the deposited snow, and a negative relationship between the initial snow height and the amount of accumulated snow. Furthermore, the surface roughness decreased from 4 to 2 cm throughout the spring and summer season at our study site. Finally, our study further shows that our method has several advantages over previous approaches, making it possible to demonstrate the importance of accumulation intermittency, and the potential influences of depositional processes on proxy signals in snow and ice.

scholarly journals An 800 year high-resolution black carbon ice-core record from Lomonosovfonna, Svalbard

2018 ◽  
Author(s):  
Dimitri Osmont ◽  
Isabel A. Wendl ◽  
Loïc Schmidely ◽  
Michael Sigl ◽  
Carmen P. Vega ◽  
...  
Keyword(s):  
High Resolution ◽  
Black Carbon ◽  
20Th Century ◽  
Biomass Burning ◽  
Ice Core ◽  
Ice Cores ◽  
The Arctic ◽  
Snow Albedo ◽  
Decadal Scale

Abstract. Produced by the incomplete combustion of fossil fuel and biomass, black carbon (BC) contributes to Arctic warming by reducing snow albedo and thus triggering a snow-albedo feedback leading to increased snow melting. Therefore, it is of high importance to assess past BC emissions to better understand and constrain their role. However, only few long-term BC records are available from the Arctic, mainly originating from Greenland ice cores. Here, we present the first long-term and high-resolution refractory black carbon (rBC) record from Svalbard, derived from the analysis of two ice cores drilled at the Lomonosovfonna ice field in 2009 (LF-09) and 2011 (LF-11) and covering 800 years of atmospheric emissions. Our results show that rBC concentrations strongly increased from 1860 on due to anthropogenic emissions and reached two maxima, at the end of the 19th century and in the middle of the 20th century. No increase in rBC concentrations during the last decades was observed, which is corroborated by atmospheric measurements elsewhere in the Arctic but contradicts a previous study from another ice core from Svalbard. While melting may affect BC concentrations during periods of high temperatures, rBC concentrations remain well-preserved prior to the 20th century due to lower temperatures inducing little melt. Therefore, the preindustrial rBC record (before 1800), along with ammonium (NH4+), formate (HCOO−) and specific organic markers (vanillic acid (VA) and p-hydroxybenzoic acid (p-HBA)), was used as a proxy for biomass burning. Despite numerous single events, no long-term trend was observed over the time period 1222–1800 for rBC and NH4+. In contrast, formate, VA and p-HBA experience multi-decadal peaks reflecting periods of enhanced biomass burning. Most of the background variations and single peak events are corroborated by other ice-core records from Greenland and Siberia. We suggest that the paleofire record from the LF ice core primarily reflects biomass burning episodes from Northern Eurasia, induced by decadal-scale climatic variations.

scholarly journals An 800-year high-resolution black carbon ice core record from Lomonosovfonna, Svalbard

2018 ◽  
Vol 18 (17) ◽  
pp. 12777-12795 ◽  
Author(s):  
Dimitri Osmont ◽  
Isabel A. Wendl ◽  
Loïc Schmidely ◽  
Michael Sigl ◽  
Carmen P. Vega ◽  
...  
Keyword(s):  
High Resolution ◽  
Black Carbon ◽  
20Th Century ◽  
Biomass Burning ◽  
Ice Core ◽  
Ice Cores ◽  
The Arctic ◽  
Snow Albedo ◽  
Decadal Scale

Abstract. Produced by the incomplete combustion of fossil fuel and biomass, black carbon (BC) contributes to Arctic warming by reducing snow albedo and thus triggering a snow-albedo feedback leading to increased snowmelt. Therefore, it is of high importance to assess past BC emissions to better understand and constrain their role. However, only a few long-term BC records are available from the Arctic, mainly originating from Greenland ice cores. Here, we present the first long-term and high-resolution refractory black carbon (rBC) record from Svalbard, derived from the analysis of two ice cores drilled at the Lomonosovfonna ice field in 2009 (LF-09) and 2011 (LF-11) and covering 800 years of atmospheric emissions. Our results show that rBC concentrations strongly increased from 1860 on due to anthropogenic emissions and reached two maxima, at the end of the 19th century and in the middle of the 20th century. No increase in rBC concentrations during the last decades was observed, which is corroborated by atmospheric measurements elsewhere in the Arctic but contradicts a previous study from another ice core from Svalbard. While melting may affect BC concentrations during periods of high temperatures, rBC concentrations remain well preserved prior to the 20th century due to lower temperatures inducing little melt. Therefore, the preindustrial rBC record (before 1800), along with ammonium (NH4+), formate (HCOO−) and specific organic markers (vanillic acid, VA, and p-hydroxybenzoic acid, p-HBA), was used as a proxy for biomass burning. Despite numerous single events, no long-term trend was observed over the time period 1222–1800 for rBC and NH4+. In contrast, formate, VA, and p-HBA experience multi-decadal peaks reflecting periods of enhanced biomass burning. Most of the background variations and single peak events are corroborated by other ice core records from Greenland and Siberia. We suggest that the paleofire record from the LF ice core primarily reflects biomass burning episodes from northern Eurasia, induced by decadal-scale climatic variations.

scholarly journals NEEM to EastGRIP Traverse – spatial variability, seasonality, extreme events and trends in common ice core proxies over the past decades

2021 ◽  
Author(s):  
Helle Astrid Kjær ◽  
Patrick Zens ◽  
Samuel Black ◽  
Kasper Holst Lund ◽  
Anders Svensson ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Forest Fire ◽  
Forest Fires ◽  
Barents Sea ◽  
Ice Core ◽  
Flow Analysis ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Anthropogenic Contamination ◽  
The Past

Abstract. Greenland ice cores provide information about past climate. However, the number of firn and ice cores from Greenland are limited and thus the spatial variability of the chemical impurities used as proxies is largely unconstrained. Furthermore, few impurity records covering the past two decades exist from Greenland. We have by means of Continuous Flow analysis investigated 6 shallow firn cores obtained in Northern Greenland as part of the NEEM to EastGRIP traverse in 2015. The oldest reach back to 1966. The annual mean and quartiles of the insoluble dust, ammonium, and calcium concentrations in the 6 firn cores spanning a distance of 426 km overlap, and also the seasonal cycles have similar peaks in timing and magnitude across sites. Peroxide (H2O2) is accumulation dependent and varies from site to site and conductivity, likely influenced by sea salts, also vary spatially. The temporal variability of the records is further assessed. We find no evidence for increases in total dust concentration, but find an increase in the large dust particle fluxes that we contribute to an activation of Greenland local sources in the recent years (1998–2015). We observe the expected acid and conductivity increase in the mid 70’s as a result of anthropogenic contamination and the following decrease due to mitigation. After detrending using the five year average the conductivity and acid records several volcanic horizons were identified and associated with Icelandic eruptions and volcanic eruptions in the Barents sea region. By creating a composite based on excess ammonium compared to the five year running average, we obtain a robust forest fire proxy associated primarily with Canadian forest fires (R = 0.51). We also note that the peak ammonium in the individual firn cores appear more scattered between cores than the peak volcanic layers, suggesting that the forest fire signal is more dispersed in the atmosphere than the acid from volcanic eruptions.

scholarly journals An investigation of rapid warm transitions during MIS2 and MIS3 using Greenland ice-core data and the CLIMBER-2 model

2002 ◽  
Vol 35 ◽  
pp. 398-402 ◽  
Author(s):  
Irene A. Mogensen ◽  
Sigfüs J. Johnsen ◽  
Andrey Ganopolski ◽  
Stefan Rahmstorf
Keyword(s):  
High Resolution ◽  
Time Scale ◽  
Ice Core ◽  
Ice Sheet ◽  
Younger Dryas ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Warm Climate ◽  
Model Simulations ◽  
Earth’S Climate

AbstractIn the search for abetter understanding of the dominant mechanisms of the Earth’s climate system, we present a study of rapid warm-climate transitions to Dansgaard– Oeschger events as seen in the ice cores from the Greenland ice sheet. We present a continuous δ18O record from the Greenland Icecore Project (GRIP) core with a resolution of 5 years until 50 kyr BP and of 20 years until 100 kyr BP. These data are compared with other high-resolution records, i.e. the Greenland Ice Sheet Project II (GISP2) chemistry record (25 years until 50 kyr BP) and the GRIP Ca2+ record (3 years until 100 kyr BP). All records have been transformed to the GISP2 Meese/Sowers time-scale. the high-resolution records are separated into interstadials and stadials, defined by the GRIP and GISP2 δ18O records. We examine in detail the transitions into the Dansgaard–Oeschger events, and propose a scenario for the changes that occur in the different ice-core records during the approximately 50 years the transition takes. Themain difference from previous studies is the much higher-resolution datasets available until 50 kyr BP; previous high-resolution studies by Taylor and others (1997) have focused on only the Younger Dryas/Preboreal transition. the data are compared to model simulations of the Dansgaard–Oeschger events performed with the CLIMBER-2 model of intermediate complexity (Petoukhov and others, 1998 ; Ganopolski and Rahmstorf, 2001).

Sign in / Sign up

Export Citation Format

Share Document